Population dynamical behavior of non-autonomous Lotka-Volterra competitive system with random perturbation

In this paper, we consider a non-autonomous stochastic Lotka-Volterra competitive system dxi(t) = xi(t)[(bi(t)¡ nPj=1aij (t)xj (t))dt+¾i(t)dBi(t)], where Bi(t) (i = 1; 2; ¢ ¢ ¢ ; n) are independent standard Brownian motions. Some dynamical properties are discussed and the su±cient conditions for the existence of global positive solutions, stochastic permanence, extinction as well as global attractivity are obtained. In addition, the limit of the average in time of the sample paths of solutions is estimated

A Thermo-labile Process in Dark Germination of New York Lettuce Seeds (A. NATURAL SCIENCE)

A thermo-labile process, that determines the level of dark germination of New York lettuce seeds, was separated from the other miscellaneous processes during germination. It began 2hr after the start of imbibition, and completed several hr before the radicle protrusion at 15℃. The optimum temperature of the process was 15℃, and the activity of the process was zero at 28℃. Secondary dormancy may by induced by the reversible inactivation of the process at high temperature. It was suggested that the physiological role of the process is the generation of the growth potential of embryonic axes in order to overcome the restraint imposed by seed coats

Systematic Analysis of the Metallic Ions by the Alkaline Method : An Attempt on Experiments in General Chemistry (A. NATURAL SCIENCE)

In analytical practice for the students, a method for the systematic separation of cations has been proposed using non-sulfide as the group reagents. This procedure was named the alkaline method, and was designed with the caution so as not to contaminate the environment, employing only the usual laboratory reagents and apparatus. Except for the six poisonous metals such as As, Cd, Hg, Bi, Sb, and Cr, seventeen kinds of common cations were divided into five groups by hydrochloric acid, ammonium hydroxide, sodium sulfite, and sodium hydroxide, and were detected succeedingly

住宅における自然換気量及び大気浮遊粉塵濃度の測定(B. 生活科学)

We have measured CO_2 concentrations of the neighboring three rooms in a dwelling house simultaneously. The ventilation volumes of these rooms are deduced from the observed changes of CO_2 concentrations. By taking into account the effects of diffusion and flow on a ventilation, the observed changes of CO_2 concentrations are reproduced very well. At the same time, mass concentrations of airborne dust were also measured inside and outside of the dwelling house. The mass concentration ratio of airborne dust inside of the dwelling house to outside was ranging from 0.3 to 0.4,which agreed very well with our previous measurements. It was found that mass concentration of windward room was higher than that of downwind one. Such difference is interpreted qualitatively by the deduced air flow from the ventilation measurement

風船法による住宅の自然換気量の測定(B. 生活科学)

Natural ventilation of a dwelling house has been measured by using CO_2 gas method. To avoid an increase of the atmospheric pressure of the room, a balloon which was filled with CO_2 gas under the same pressure was employed as a CO_2 gas source. The measurement was carried out with a remote control system. The measured decrease of the CO_2 gas concentration was reproduced by sum of two exponential components and constant background level, which indicates that the ventilation of the room is affected at least by three states including the relevant room, surrounding atmosphere and the neighbouring room. We applied two room model, i.e. three states model instead of simple one room model, to analyse the observed decay of CO_2 gas concentration

分子軌道法による化学吸着の研究(A. 理学)

A molecular orbital study was carried out to investigate the chemisorption of gaseous molecules onto the transition metal surfaces. In the adsorption of hydrogen, ethylene and carbon monoxide onto the nickel and platinum surfaces, the bonding of adsorbates was remarkably weakened at the sites of surface defects called steps and kinks. The mechanism of the bond weakening was explained in terms of the charge transfer between the adsorbate and the surface atoms. The chemisorptive interactions of the transition metals with the different number of d electrons were examined and compared with each other. The adsorption of acetylene and carbon monoxide was investigated using the nickel, platinum and tungsten surfaces. The d orbitals of nickel and platinum contribute to only the charge transfer from metal surfaces to adsorbates, while they contribute to the charge transfer in both directions in tungsten. So the interactions were much stronger than those in nickel and platinum, and the dissociation of adsorbed molecules was much easier in tungsten